钛基复合材料激光熔覆层显微组织及其强化机制

利用激光熔覆技术在Ti-6A1-4V合金表面制备了TiC增强钛基复合材料涂层，复合材料的硬度明显高于基体，平均硬度可达940HV0.2。对复合材料的显微组织分析表明：TiC增强钛基复合材料的强化机制以细晶强化和弥散强化为主。     

AlSi7Mg合金半固态压铸件热处理强化机理研究

对AlSi7Mg合金(A356)半固态压铸件和液态压铸件进行了不同工艺的固溶与时效热处理，分析了其显微组织与疏松度，测定了硬度、拉伸强度及延伸率等力学性能。实验得出，铝合金半固态压铸件原始态的力学性能优于液态压铸件，并且半固态压铸件时效强化效果尤其明显，拉伸强度可达330MPa以上，延伸率10％以上。这主要是由于半固态压铸件比液压件具有更加致密，且为球状的非树枝晶组织。铝合金半固态压铸件时效强化，机理主要归于弥散析出Mg2Si强化相。     

高强高导Cu-0.1Ag-0.11Cr合金的强化机制

Cu-Ag-Cr合金是一种高强度高电导新型材料.采用真空熔炼的方法制备了Cu-Ag-Cr合金,经合适的工艺处理后,在电导率基本上不降低的前提下,能显著提高合金的强度和硬度,抗拉强度达到529 MPa,电导率为92.11%(IACS),基本满足对铜合金高强高导的性能要求.在同样条件下,与Cu-Ag合金相比,其强度和硬度的提高主要是由共格析出强化造成,由于析出相尺寸较大,以Orowan机制强化,强化效应与采用Orowan强化机制计算的结果非常接近.     

几种模具表面强化新技术的简介

本文从电火化、热喷涂、金属表面喷丸，等离子化学热处理，离子注入，TD处理、气相沉积、激光表面处理等几方面介绍了提高模具使用寿命的表面强化新技术。     

Oxidation and hot corrosion of coated and bare oxide dispersion strengthened superalloy MA-755E

Cyclic hot corrosion and oxidation testing of an experimental oxide dispersion strengthened (ODS) superalloy MA-755E were conducted in a hot gas stream at Mach 0.3. The response of the ODS alloy, bare or with protective coatings, was similar to that of a conventional cast alloy, IN-792, in hot corrosion at 900°C. However, during oxidation at 1100 and 1150°C the ODS alloy differed from the cast alloy by developing a greater amount of subsurface porosity. Compared with a diffused aluminide coating, an electron beam vapor deposited NiCrAlY coating offered superior oxidation protection and decreased porosity formation. In additional testing, the tendency to form porosity was associated with the large grains of recrystallized powder metallurgy alloys but was independent of the presence of an oxide dispersion.     

电刷镀纳米晶镀层的组织及其强化机理

采用直流、脉冲和脉冲换向电流制备了Ni和n—SiO2／Ni电刷镀镀层，利用SEM、AFM、TEM和XRD等技术对镀层的表面形貌、显微组织和晶粒尺寸等进行了分析测量。结果表明，电刷镀层表面呈胞状组织，镀层的晶粒尺寸均在纳米量级，说明电刷镀技术是一个古老而未被认识的纳米技术；复合电刷镀过程中纳米颗粒的作用及脉冲换向电流，能进一步提高镀层的形核率及抑制晶粒的生长，从而减小纳米晶的尺寸。镀层的硬度与纳米晶的尺寸有很好的对应关系。     

"KQDL系列冲天炉"成果研讨

针对冲天炉,冷风炉、热风炉、水冷却炉存在的问题试制出了"KQDL系列冲天炉".论述了"KQDL系列冲天炉"采用空气冷却、强化预热、单排龙卷风供风原理和特点.通过生产实践与传统冲天炉的比较,认为这种新型冲天炉可给企业带来明显的经济效益,同时可使铁水质量明显提高,这种新型冲天炉有很高的性价比,可使冲天炉的设计更上一层楼.     

Y2O3／CeO2复合强化钼合金（MYC）丝的研究

采用粉冶法制备了添加Y2O3／CeO2(≤0．6w％)的复合强化钼合金(MYC)丝。用XRD标定合金相组成，用SEM观察合金的显微组织，用万能电子拉伸机测定合金丝的力学性能并将测定结果与纯钼丝进行了对比研究。研究结果表明：添加Y2O3／CeO2复合强化钼合金的相组成为Mo，YMoO4和CeO2；MYC合金断口具有典型的塑性断裂特征，MYC合金丝在1600℃退火后仍然表现明显的纤维状织构组织形态。     

扩散处理对Si3N4陶瓷与金属钎焊接头的强化作用

用扫描电子显微镜、能谱仪及X射线衍射仪分析和讨论了复合电镀Ni-Ti陶瓷与金属钎焊接头的强度、微观结构和其界面结合机制。试验表明：扩散处理对陶瓷与金属钎焊接头有强化作用。经辉光扩散处理后，Ti向陶瓷界面扩散，Ni-Ti层与陶瓷发生界面反应。     

New development in welding thin-shell aluminum alloy structures with high strength

From the viewpoint of welding mechanics, two new welding methods-welding with trailing peening and welding with trailing impactive rolling were introduced. For aluminum alloy thin-shell structures with high strength, welding will lead to hot cracking, poor joint and distortion. In order to solve them, trailing impactive device was used behind welding torch to impact the different positions of welded joints, thus realizing the welding with free-hot cracking, low distortion and join tstrengthening. By use of impactive rolling wheels instead of peening heads, the outlook of welded specimen can be improved and stress concentration at weld toes can be reduced. Equipment of this technology is simple and portable. It can used to weld sheets, longitudinal and ring-like beams of tube-like structures, as well as the thin-shell structures with closed welds such as flanges and hatches. So the technology has the wide application foreground in the fields of aviation and aerospace.